Halogeno-o-phenylenediamines and derived heterocycles. Part I. Reductive fission of benzotriazoles to o-phenylenediamines

Abstract

Halogeno-o-phenylenediamines and Derived Heterocycles.

Polychloroheteroaromatic Compounds

“…Thus, from tetrachloro-o-phenylenediamine can be prepared the tetrachlorocompounds (298) listed in Table 2.6 [643,644]. The product (299) from the reaction between tetrachloro-o-phenylenediamine and glyoxylic acid yields 2,5,6,7 ,8-pentachloroquinoxaline (300) on treatment with a phosphorus oxychloride-phosphorus pentachloride mixture [643,644].…”

“…Thus, from tetrachloro-o-phenylenediamine can be prepared the tetrachlorocompounds (298) listed in Table 2.6 [643,644]. The product (299) from the reaction between tetrachloro-o-phenylenediamine and glyoxylic acid yields 2,5,6,7 ,8-pentachloroquinoxaline (300) on treatment with a phosphorus oxychloride-phosphorus pentachloride mixture [643,644]. Likewise, the product (301) from the reaction between the a-phenylenediamine and ethyl oxalate yields hexachloroquinoxaline [643], whilst the product from the reaction between 3,5-dichloro-o-phenylenediamine and oxalic acid gives 2,3,5,7-tetrachloroquinoxaline (302) [642].…”

“…The product (299) from the reaction between tetrachloro-o-phenylenediamine and glyoxylic acid yields 2,5,6,7 ,8-pentachloroquinoxaline (300) on treatment with a phosphorus oxychloride-phosphorus pentachloride mixture [643,644]. Likewise, the product (301) from the reaction between the a-phenylenediamine and ethyl oxalate yields hexachloroquinoxaline [643], whilst the product from the reaction between 3,5-dichloro-o-phenylenediamine and oxalic acid gives 2,3,5,7-tetrachloroquinoxaline (302) [642]. The 6-substituted compounds (303; R = Me, Br, F, OMe) may be prepared similarly from the appropriately substituted trichloro-o-phenylenediamine [643,644] .…”

“…Likewise, the product (301) from the reaction between the a-phenylenediamine and ethyl oxalate yields hexachloroquinoxaline [643], whilst the product from the reaction between 3,5-dichloro-o-phenylenediamine and oxalic acid gives 2,3,5,7-tetrachloroquinoxaline (302) [642]. The 6-substituted compounds (303; R = Me, Br, F, OMe) may be prepared similarly from the appropriately substituted trichloro-o-phenylenediamine [643,644] . These in tum can be conveniently synthesized by reduction of …”

“…the corresponding polychlorobenzotriazole (Section 2.18.1) with zinc and acid [643]. Oxidation of 5,6,7,8-tetrachloroquinoxaline with either nitric acid or hydrogen peroxide yields the dione (301) [643], whilst treatment of hexachloroquinoxaline with anhydrous potassium fluoride in an autoclave at high temperatures gives hexafluoroquinoxaline [639][640][641].…”